Colecovision failing to power on--again?!

[Yosikuma]

Hi, remember me? Months back I picked up a super junky Colecovision that would only sometimes power on, and got to the point where it was not powering on at all. It would send a black screen (which would lose sync), but things like the SGM or the wafer drive would never show power in this condition.

 

So I picked up a new system. Great price, possibly the cleanest Colecovision I have ever seen. Great score, right? Got to play it loads last night.

 

Aaaaaaaand now tonight I am getting the same lack of powering on.

 

I have no idea what to think here, but I welcome theories or assistance in breathing life into this thing once again. It is certainly suspicious that I have the same exact problem with two different machines. -_-

[Ikrananka]

Again, very likely the power switch. First thing I'd do is to dismantle and clean it.

 

Do you have a multimeter? You can test for voltage at various points around the motherboard to trace and verify what the issue is.

 

How are your soldering skills?

[Pixelboy]

Also, are you using the same power supply on both your CVs?

[Yosikuma]

The first CV had a power supply that was wired into the system. It was an odd job, for sure. This one has no such things but the system looks clean and, again, 24 hours beforehand worked just fine. Sadly my soldering skills are nonexistent.

[ChildOfCv]

You can also check the voltages in the expansion slot, so you don't even have to disassemble the CV for a basic power test. The big contact on top is gnd, and the first 3 contacts on the bottom from left are -5, +5, and +12.